The present invention relates to a "goods-handling" door for an industrial building such as a factory, a workshop, a warehouse, a hangar, or the like, to enable a bay cut out in a wall to be closed or opened.
A door of this type comprises a curtain that must be capable of being raised and lowered quickly to allow vehicles to pass through, while remaining open as short a time as possible so as to restrict the passage of noise and air between two premises or between the inside and the outside. The curtain is flexible or made up of rigid panels, and it is capable of being wound up or folded up at the top of the door. The curtain may optionally be reinforced by horizontal stiffening bars. At its top, the door includes mechanical members: a motor, a shaft for winding up the curtain or curtain-raising straps, a stepdown gear box, end-of-stroke detector means, etc. . . . . Slideways are provided on either side of the door to guide the edges of the curtain, and optionally also the ends of stiffening bars. The slideways may optionally form vertical side uprights with the mechanical elements being fixed to the tops thereof. The tops of the uprights may be interconnected by a top cross-beam. The beam may also be fixed to the wall, above the door or on either side thereof.
The uprights are usually placed against the wall, at the edges of the opening constituted by the bay, and they may optionally be within the opening in the thickness of the wall, against the end section thereof. This disposition is uncommon since it reduces the available area in the opening.
In certain industries, such as the pharmaceutical, food, chemical, etc. industries, it is necessary to clean the elements of the door completely on a regular basis. Unfortunately, it is not possible to clean the gap between one of the sides of an upright and the portion of the wall against which it is placed. An object of the present invention is to enable such cleaning to be performed completely.
When a vehicle comes up to the door, the curtain is generally raised automatically and the vehicle can pass through almost without slowing down, with the door closing again after the vehicle has gone through. Nevertheless, it can happen that the vehicle is travelling too fast, and that it strikes the curtain before it has been raised far enough. Means and dispositions have already been proposed to limit the physical damage suffered by the door under such circumstances. In one proposal, the slideways may be flexible, allowing the curtain to escape if excessive force is applied thereto (European patent EP-0 272 733 ). In another proposal, the stiffening bars of the curtain may be flexible, so they flex to escape from the slideways if they are subjected to too great a force (EP-0 398 791 ). Hinged doors have also been proposed in which the hinges come undone if they are subjected to too much force (FR-1 196 095 ).